The present invention generally relates to an image forming apparatus, e.g., an electrophotographic copying apparatus and the like, and more particularly, to a cartridge unit which accommodates therein as one unit, a photoreceptor drum and at least a cleaner unit with the various components disposed around the photoreceptor drum, so as to be detachably mounted with respect to a main body of the image forming apparatus.
In a recent image forming apparatus such as a compact size copying apparatus or the like, it has been proposed to employ a cartridge unit arranged to be replaceable at the user's side without the necessity for calling servicing personnel even when the replacement time of components, such as a photoreceptor drum, etc., has arrived, from the viewpoint of a maintenance-free operation. By forming such a cartridge into one unit with the photoreceptor drum and a cleaner unit or the like including a used toner accommodating portion which is one of the parts required to be replaced after a predetermined period of time, there is the advantage that at the user's side, when it becomes necessary to replace those parts, the entire cartridge unit may be readily replaced by the user, without the necessity for calling servicing personnel.
Conventionally, although a cartridge unit integrally formed with the photoreceptor drum, cleaner unit or a first corona charger has been proposed, there has not been proposed a cartridge unit in which a separation unit for separating a copy paper sheet after transfer is incorporated therein as one unit. Therefore, when the photoreceptor drum has served its life, the situation may be readily adjusted to by replacing the entire cartridge unit, but in the case where a copy paper separation unit is soiled by toner, etc., it has been necessary to call servicing personnel in for cleaning. Particularly, in an image forming apparatus employing a separating tape for effecting the separation, cleaning is required periodically, since the separating tape and separating roller, etc., tend to be soiled by toner, but it has been very difficult for the user to clean such portions.
Moreover, there has been an inconvenience such that, although the positioning of the separation unit must be highly accurate owing to the relation thereof with respect to the photoreceptor drum, in the arrangement in which the photoreceptor drum is detachable as the cartridge unit, with the separation unit remaining fixed to the image forming apparatus main body, positional accuracy of the separation unit can not be sufficiently achieved.